ABSTRACT: The isolated dystonias (previously known as primary dystonias) are a diverse group of rare disorders characterized by involuntary, sustained muscle contractions that may cause twisting and repetitive movements, sustained movements or abnormal postures. These isolated dystonias typically begin in different body parts including the face, neck, larynx or limbs but the risk of spread and the natural history of these disorders mostly come from retrospective reviews limited by relatively few patients seen at any one clinical site. The primary purpose of this project is to extend our prospective natural history studies of 4 isolated dystonias: blepharospasm (BSP) that begins in the upper face; cervical dystonia (CD) that begins in the neck; laryngeal dystonia (LD) that begins in the larynx; and limb dystonia that begins in the one of the limbs. This Natural History project will use web-based tools already developed for the Dystonia Coalition (DC) to collect demographic, clinical, and video data from existing sites in the U.S.A., Canada, Australia, Italy, Germany, France and the U.K. Recruitment for each subtype of isolated dystonia will be capped to ensure broad distribution of all subtypes adequate to address our primary questions. We will collect data via a web-based secured system that has met the requirements of our U.S. and international recruiting sites. Although the primary purpose of this project is to determine the natural history of these isolated dystonias, we also provide easy access to data to facilitate collaborations through data sharing with investigators within and external to the DC, as we have successfully done. Past recruitment combined the efforts of 37 international sites to collect demographic, clinical, rating scale, video and biosample data from more than 3000 people with isolated dystonias. We have substantial preliminary data on the natural history of the isolated dystonias with the greatest amount of data from people with CD. This proposal for ?Natural History of the Isolated Dystonias? will extend and enhance these studies. We propose 5 specific aims: 1) determine the natural history of BSP; 2) determine the natural history of CD; 3) determine the natural history of LD; 4) determine the natural history of limb dystonia; and 5) facilitate sharing of data with investigators within and external to the DC. This project permits studies of the different isolated dystonias and facilitates comparisons across these disorders. We also will continue to partner with private patient advocacy groups to support data collection at collaborating sites.